以泗抗1号(常规品种)和泗杂3号(杂交种)为材料,于盛铃期用高温低湿度和低温低湿度2个处理胁迫棉株48 h,研究叶片氨基酸组分的变化及其与Bt蛋白含量的关系.结果表明,温湿度胁迫大幅度增加了叶片中天冬氨酸、谷氨酸、丙氨酸及精氨酸含量,对丝氨酸、苏氨酸、缬氨酸含量无明显影响,亮氨酸、异亮氨酸含量小幅下降.低温低湿度胁迫12 h后叶片Bt蛋白含量发生显著下降,而高温低湿度处理胁迫24 h后下降幅度较大；整个胁迫过程中,低温低湿度下叶片Bt蛋白含量一直低于高温低湿度处理.温湿度胁迫还降低叶片GPT和GS酶活性,但提高了蛋白酶的活性.相关性分析表明,温湿度胁迫叶片中Bt蛋白主要氨基酸组分总量与Bt蛋白含量呈显著负相关关系.说明盛铃期湿度胁迫叶片Bt蛋白含量的下降与Bt蛋白合成能力下降、分解能力增强相关.%The purpose of this study was to investigate how high temperature with low humidity stress and low temperature-humidity stress for 48 hours on leaf amino acids content and the relationship between Bt protein content and amino acids content using two Bt cotton cultivars in plant growth chamber, one was conventional ( Sikang 1) , other was hybrid (Siza 3 ). The results showed that combination stress of temperature and humidity stress increased sharply the content of Asp, Glu, Ala and Arg, but decreased the content of Leu and He, and had no significantly effect on the content of Ser,Thr and Val. The combination stress of temperature and humidity stress had significantly effect on the leaf Bt protein content in peak boll period. Leaf Bt protein content was decreased under low temperature-humidity stress after 12 hours significantly, while that of high temperature with low humidity stress dropped sharply after 24 hours. Leaf Bt protein content of low temperature-humidity treatment was lower than that of high temperature with low humidity treatment during stress time. The combination stress of temperature and humidity significantly decreased activity of the GPT and GS, but increased protease activity. There existed significantly negative correlation between total content of main amino acids of Bt protein and Bt protein content. These results suggested that the decrease of leaf Bt content under combination stress of temperature and humidity was closely associated with the decrease of Bt protein synthesis ability and the increase of Bt protein decomposition.
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